Lock washer



May 1, 1928. 1,668,025

c. G. OLSON LOCK WASHER Filed Feb. 4, 1927 a v Z INVENTOR (hr! 6 Olson,

Patented May-1, 1928.

UNITED STATES PATENT OFFICE.

cm G. OLSON, O1 CHICAGO, ILLINOIS, ASSIGNOR TO SHAKEPROOI' LOOK WASHER COMPANY, INCORPORATED, DIVISION 01. ILLINOIS TOOL WORKS, OI CHICAGO, mmors, A CORPORATION 01 ILLINOIS.

LOOK wasnan.

Application filed February 4, 1927. Serial. Io. 105,886.

This invention pertains to lock washers of the kind that prevents reverse rotation of a threaded nut or bolt by locking the nut or bolt head to the'substructure by the biting action of a number of rigid teeth that project above both surfaces of the washer, the teeth on one surface being disposed intermediate the teeth on the other surface so that upon compression under the nut or bolt headthe washer assumes a corrugated or wav form.

T e improvement over the former art, embodied in my invention, is found in a novel shape and arrangement of the teeth with res ect to the body of the washer. The bo y itself, as usual in washers of the abovementioned type, is made of an. annular ring of sprin material, for instance, sheet steel. An ob ect of my inventionis to provide in a washer of the kind described, teeth that are not struck up or milled from the face of .the annular ring itself, as has heretofore been the practice, but instead lie beyond the circular boundaries of the ring,yet are inte gral with it. The advantage of this tooth arrangement is that the ring and the teeth can be formed from sheet metal by a simple stamping o eration, and furthermore the strength an springiness of the ring pro er is not impaired, as heretofore,by 'strikihg up the "teeth irom the ring material, or by iorcin the rojections up from the oppositesieoftering.

- Another object is toprovide in combination with the annular ring or bod of the washer a series of teeth, in :le as a ove described and shaped by bending to afford maximum strength for resisting compression, so that when the washer: is compressed its' annular body will be sprung out of its normal flat condition into a wavy or corrugated sha e. The utilization of oppo- Feitely place alternating, ratchetbiting teeth for springing a flat washer into corruated form un er compression is not, broadconsidered, new in this embodiment, but

-the utilization of biting teeth that are located radiall beyond the peripheral bounda of the at annular ring, the said teeth being formed "by bending them alternately in opposite directions out of the plane of the ring so that /a compressive load applied simultaneously-to the points of all the teeth will spring the ring from flat into wavy corrugated form, is believed to be new in the art. I

By this construction the teeth are presented endwise to the compressing surfaces, and will resist enormous stresses without buckling or breaking. Moreover, the compressive'loading ofthe teeth is resisted by the full strength of the washer body to resist bending, whereas in former constructions, in which the teeth extended across the face of the ring, the spring-strength of the washer body was weakened by. the act of forming the teeth from the material of the ring proper.

With the fore oing and certain other objects in view, whlch will appear later in the specifications, my invention comprises the.

devices described and claimed and the equivposition between two bodies, as the base of a nut or bolt head and the substructure, before the final tightening operation.

Fig. 3 is a similar view, showing the form the washer assumes on the final tightening of the nut. e

Figs. 4 and 5 are cross sections respectively on lines 44 and 55 of Fig. 1.

As is clearly shown in the drawm the annular ring or washer body 1, pre erably made by stamping out of spring sheet metal, has on its outer periphery a number of pairs of oppositely directed teeth 2, 3. I In Fig. 1 the she e and position of the tooth blanks, in the at, are designated by dotted lines.

A tooth 2 of each pair is bent upwardly subinner and outer circlesthat define the ring proper, yet when the compressive stress is applied to the biting edges of the teeth the body of the spring ring itself is sprung into the corrugated 'or wavy form shown in Fig. 3.

y this means the full reactionary strength of the ring is utilized to cause the teeth to powerfully bite into the faces of the work, ecause the rin itself has not been weakened either by punc ing teeth from its body as in some former constructions, or'by forcing up the metal of the ring'from the opposite side to form the teeth, as in other earlier constructions.

In my. inventionthe construction of the teeth and their preferred arrangement around the rim of the washer ring possess certain novel features, as follows: Referring to the tooth blank shown b dotted lines in Fig. 1, it is clear that toot 2 when bent up at right angles to the plane of the ring, as shown in Fig. 4, hasa biting edge 6, an upright front face '7 and a rearwardly sloping reinforcing body 8, and that or heel 10 and its biting edge 6 rigidly ena g Y o and 5, whiIe thetendency of the work to unaged between the opposing work faces 4 screw is resisted by compression withinthe oppositely directed and mutuall reinforcing teeth 2 and 3, as indicated by t e arrows in Fig. 3. These opposing thrusts are withstood by the teeth themselves. consequent ly there is no serious strain brought upon the Washer body 1. It is, therefore, free to .exert all of its springy or elastic strength,when sprung into the wavy formshown in Fig. 3,

in holding the bitingedges of the teeth in engagement with the work after some slight unscrewing movement has taken place, or even before the full amount of compression illustrated in Fig. -3.has occurred, that is, before the nut has been solidly screwed to its seat.

By the means above described I have produced a washer that can be made from sheet metal by simple stamping or punch press operation; the bod or ring proper is not altered or distorte to make the teeth and con sequently retains its full initial spring strength. The teeth, although lying outside the ring are capable of springing it into wav form under com ression, and the shape of t e teeth is such t at. the two teeth of a pair mutually reinforce each other so as to withstand the thrust caused by tendency of the nut to unscrew, and by resisting that thrust the teeth relieve the washer body of that str'ain, yet all downward load is transmitted directly from the points of the teeth to the washer body to sprlng it or corrugate rected and rojecting downwardly out of the plane 0 the body, said pair, of teeth adapted, when subjected to compressive load, to spring the body of the washer into sllghtair bent so as to be substan- 1y corrugated form, for the purposes set forth.

2. A spring lock washer comprisin an annular ring of flexible material, a plurality of pairs of teeth spaced around an outside the peripher of said ring, each pair formed from a radia ly'projecting ring portion having an angular notch in its outer edge,the tooth members of said ring bent to project at right angles to the plane of the washer in opposite directions therefrom, for the purposes set forth.

3. A spring lock washer comprising a flat annular ring having biting teeth spaced apart around its periphery, said teeth located radially beyond the peripheral boundary of the ring, individual teeth of each pair bentsubstantially at-a right angle with the plane of said body and projecting in opposite directions therefrom and so disposed that the compressive action of the work upon the oppositely directed teeth causes slight rotation of each pair of teeth and consequent deflection of that part of the ring between adjacent pairs of teeth, for the purposes set forth.

In testimony whereof, I affix my signature.

' CARL G. OLSON. 

